In recent years, many offices have exchanged their copiers, printers, facsimile machines, scanners, etc. for a single document-processing device that is able to support multiple functionalities. For example, offices may replace the typical facsimile machine, walk-up copier, scanner, and individual network printers, with a single machine, referred to as a multi-functional document-processing device or a Mopier®.
Such multi-functional document-processing devices are capable of facilitating multiple users. However, each user must wait for their turn, thereby causing some users to wait before they can use the device. For example, since a typical multi-functional document-processing device has only one print engine, the device can only produce one print output at a time. In other words, only one job may be sent through a print path at a time. Thus, a walk-up copier user who wishes to use the scanning and copying functions available on the device must wait until the device has completed other tasks, such as printing a print job, before the walk-up user may begin scanning the pages of their copy job. A large print job may engage the device for a long period of time and may cause a backlog of operators waiting for their turn to copy on the device. Similarly, when the device is warming up in preparation to print a job or is in a power-save mode, a walk-up copier user must wait for the device to complete its warming-up process prior to being able to scan a document.
Some document-processing devices are known which use a memory buffer to permit a user to scan their copy job into the device when the printer portion of the device is engaged in a different print job. These buffers are generally temporary storage areas that are limited in size. A typical buffer can temporarily store only a few scanned images. Thus, a walk-up user who wishes to scan a copy job while the printer portion of the device is occupied may be able to scan a few pages of their copy job. However, the walk-up user who has a large copy job, which cannot be stored in the buffer, must wait for printer portion of the device to become available.
Furthermore, multiple print jobs submitted through the network may frustrate walk-up users waiting for the printer portion of the device to become available. For example, a network user may submit a first print job to the network printer portion of the device and during the process of printing the first print job, a walk-up user may walk-up to the same device in the hopes of completing a large copy job. If the buffer is not large enough to store the copy job, the walk-up user must wait for the first print job to be completed. The walk-up user may also have to wait for print jobs submitted from a network during the printing of the first print job. Thus, if, while the walk-up user is waiting, a second and third print job are submitted to the device, then the walk-up user must now wait for not only the first print job, but also the second and third print job, and any queued print jobs.